Incumbent senator losses in the 2010 election

Two incumbents were defeated in the primaries: Utah Sen. Bob Bennett (R) and Pennsylvania Sen. Arlen Specter (D). In the general election, 23 incumbents sought reelection and only two lost (Russ Feingold and Blanche Lincoln). It may possibly be three if Lisa Murkowski loses the write-in campaign in Alaska, but so far she’s ahead in the counts.

Assuming that Murkowski wins, this means that 84% of incumbent senators won reelection this time around (21 of 25, including incumbent primary losses).

Historically-speaking, the average incumbent reelection rate in the Senate since 1954 is exactly the same: 84%. Thus, it’s hard to make an argument that this was an “anti-incumbent year” for senators. In fact, more incumbent senators lost in 2008 (5), 2006 (6) and 2000 (6) than were defeated in 2010.